InterPro domain: IPR000357

The HEAT repeat is a tandemly repeated, 37-47 amino acid long moduleoccurring in a number of cytoplasmic proteins, including the fourname-giving proteins huntingtin, elongation factor 3 (EF3), the 65 Kdalpha regulatory subunit of protein phosphatase 2A (PP2A) and theyeast PI3-kinase TOR1 [ 1 ]. Arrays of HEAT repeats consists of 3 to 36units forming a rod-like helical structure and appear to function as protein-protein interaction surfaces. It has been noted that manyHEAT repeat-containing proteins are involved in intracellular transport processes.

In the crystal structure of PP2A PR65/A [ 2 ], the HEAT repeats consistof pairs of antiparallel alpha helices [ 3 ].

1. HEAT repeats in the Huntington's disease protein. Nat. Genet. 11, 115-6
2. The structure of the protein phosphatase 2A PR65/A subunit reveals the conformation of its 15 tandemly repeated HEAT motifs. Cell 96, 99-110